R21xx-HP FlexFabric 11900 Layer 3 IP Services Command Reference

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Usage guidelines
The device can dynamically acquire the link-layer address of a neighboring node through NS and NA
messages and add it into the neighbor table.
When the number of dynamic neighbor entries reaches the threshold, the interface stops learning
neighbor information.
Examples
# Set the maximum number of dynamic neighbor entries that VLAN-interface 100 can learn to 10.
<Sysname> system-view
[Sysname] interface vlan-interface 100
[Sysname-Vlan-interface100] ipv6 neighbors max-learning-num 10
ipv6 prefer temporary-address
Use ipv6 prefer temporary-address to configure the system to generate and preferably use the temporary
IPv6 address of the sending interface as the source address of a packet.
Use undo ipv6 prefer temporary-address to disable the system from generating temporary IPv6
addresses and remove existing temporary IPv6 addresses.
Syntax
ipv6 prefer temporary-address [ valid-lifetime preferred-lifetime ]
undo ipv6 prefer temporary-address
Default
The system does not generate or use any temporary IPv6 address.
Views
System view
Predefined user roles
network-admin
Parameters
valid-lifetime: Specifies the valid lifetime of temporary IPv6 addresses in seconds, in the range of 600 to
4294967295. The default valid lifetime is 604800 seconds (7 days).
preferred-lifetime: Specifies the preferred lifetime of temporary IPv6 addresses in seconds, in the range
of 600 to 4294967295. The default valid lifetime is 86400 seconds (1 day).
Usage guidelines
With stateless address autoconfiguration enabled on an interface, the device automatically generates an
IPv6 global unicast address by using the address prefix information in the received RA message and the
interface ID. On an IEEE 802 interface (such as an Ethernet interface or a VLAN interface), the interface
ID is generated based on the MAC address of the interface and is globally unique. As a result, the
interface ID portion of the IPv6 global address remains unchanged and exposes the sender. An attacker
can further exploit communication details through the information.